Technical Abstract:
Increased energy extraction has impacted rangelands throughout the western U.S. Ecological restoration can be enhanced with proper management of affected top soils. Little information exists on effects of stockpiling on soil microbial community composition and functionality and seed bank dynamics. The objectives of this research are to assess microbial responses and seedbank dynamics in stockpiled top soils as a function of stockpile age and depth. Three study sites are located in the western Rio Grande Plains, TX. Stock piles are sampled at different depths as they age; seed banks are examined under greenhouse conditions. Samples from stock piles are evaluated for microbial community structure according to ester linked-fatty acid methyl ester (EL-FAME) profiles, enzyme activities of C and P cycling, and selected chemical properties. Stockpiling top soils has immediate impacts on microbial biomass carbon and nitrogen as well as on microbial community composition. These effects depend on soil series and depth of sampling; additionally, biological characteristics of stockpiles change over time differently than do biological characteristics of intact (undisturbed) soils. Results will aid in developing guidelines for restoration of landscapes that are impacted by energy development.